crypto: rsa - limit supported key lengths
Introduce constrains for RSA keys lengths.
Only key lengths of 512, 1024, 1536, 2048, 3072, and 4096 bits
will be supported.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 752af06..466003e 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -267,12 +267,36 @@
return ret;
}
+static int rsa_check_key_length(unsigned int len)
+{
+ switch (len) {
+ case 512:
+ case 1024:
+ case 1536:
+ case 2048:
+ case 3072:
+ case 4096:
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
static int rsa_setkey(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
+ int ret;
- return rsa_parse_key(pkey, key, keylen);
+ ret = rsa_parse_key(pkey, key, keylen);
+ if (ret)
+ return ret;
+
+ if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) {
+ rsa_free_key(pkey);
+ ret = -EINVAL;
+ }
+ return ret;
}
static void rsa_exit_tfm(struct crypto_akcipher *tfm)